#include<stdio.h>
int main()
{int i=2;
    double f1[21]={1,2},f2[21]={1,1},sum=0;
    while(i<21)
    {
    f1[i]=f1[i-2]+f1[i-1];
    f2[i]=f2[i-2]+f2[i-1];
    i++;}
    for (i=1;i<21;i++)
    {sum=sum+f1[i]/f2[i];}
    printf("sum=%lf",sum);
    return 0;
}